Propulsion of screw-steamers.



No. 792,455. I PATENTED JUNE 13, 1905. A. RATEAU.

PROPULSION OF SORBW STEAMERS.

APPLICATION FILED HERB-3,1905.

4 SHEETS-SHEET l. W

BIO-792,455. I PATENTED JUNE 13, 1905. A. RATEAU.

PROPULSION OF SCREW STBA'MERS.

APPLICATION IILBD FEB. 23, 1906.

4 SHEETS-SHEET 2.

(g g jadz e zZ iw No. 792,455. V PATENTED JUNE 13, 1905.

A. RATBAU. PROPULSION 0P SGREW STBAMERS.

APPLICATION FILED 113.23. 1906.

4 BHEETSSHEET 3.

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PATENTED JUNE 13, 1905.. A. RATEAU.

PROPULSION 0P SCREW STBAMERS.

APPLICATION-FILED FEB. 23,1905.

4 SHEETS-SHEET 4.

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UNITED STATES Patented June 13, 1905.

PATENT OFFICE.

A UGUSTFJ RATEAU, OF PARIS, FRANCE.

PROPULSION OF SCREW-STEAIVIERS.

SPECIFICATION forming part of Letters Patent No. 792,455, dated June 13, 1905.

Application fil d February 23, 1905. Serial No. 247,024.

To all whom may concern:

Be it known that I, Auensrn RATEAU, engineer, a citizen of the French Republic, re siding at Paris, France, have invented certain new and useful Improvements in Propulsion of Sam Steamers, of which the following is a specification.

In the application of steam-turbines to the propulsion of ships great difiiculties are met on account of the fact that steam-turbines have a low efliciency at low speeds and are not well adapted to backward running. Thus when turbines are used the following disadvantages have to be encountered: first, a relatively exaggerated consumption of steam at low speeds; second, very imperfect backward running and difiiculty of boarding or coming alongside.

This invention has for its object to obviate completely these disadvantages by a special combination of turbines and reciprocating engines by adapting each type of engine to the kind of work for which it is most suitable. It is then possible to secure at any speed a minimum consumption of steam and to obtain with the reciprocating engines all the advantages inherent to them as regards backward running and generally all the maneuvers required for stopping the ship, boarding, or coming alongside. Y

The accompanying drawings show examples of application of the invention.

Figure 1 is a transverse section, and Fig. 2 a plan, of an engine-room of a ship fitted with three screw-propeller shafts 14 15 16, the central shaft 14 being driven by a reciprocating engine, while the two side shafts 15 and 16 are each driven by a steam-turbine. Fig. 3 is a plan of one-half of an engine-room of a ship fitted with five screw-propeller shafts, the central shaft being driven by a reciprocating engine,

while each pair of side shafts is driven by a pair of turbines working in series. Fig. L showsin elevation, and Fig. 5 in plan, a modified arrangement.

Referring to Figs. 1 and 2, the steam coming from the boiler by the pipe 1, Fig. 2, enters first the reciprocating engine 2. This engine is usually a triple or quadruple expansion engine. The drawings show, for instance,

valve-gear.

' constant.

a four-cylinder engine with two high-pressure cylinders .in parallel and two low-pressure cylinders connected to the first two cylinders. After having done work in the reciprocating engine the steam flows (at a pressure which is more or less high according to its volume) into the turbines. The current of steam divides into two parts, which are generally equal. One part goes by the pipe 3 to the turbine 4, while the other part goes to the turbine 6 through the pipe 5. Each of the pipes 3 and 5 is provided with a branch extending, respectively, to the valves 9 and 10 of reversing-turbines. When the steam has completed its expansion in the turbines4 and 6, it escapes into the condensers 11 and 12, the air and cold Water pumps of which are shown in 13. The central shaft 14 is therefore driven solely by the high-pressure reciprocating engine, while each of the side shafts 15 and 16 is driven by a low-pressure reversible turbine. The port and starboard turbines are alike.

The reciprocating engine is fitted with a reversing gear for shifting the link motion The reversible turbines are each provided with two stop-valves (7 and 9 for the left turbine, 8 and 10 for the right turbine) which can be opened and closed alternately. It will be seen that in this arrangement the high-pressure steam works in the reciprocating engine, which is more suitable than steamturbines for this pressure, and that its expansion is completed in the turbines, which permit of carrying the expansion of the steam to its lowest limit. Each of the engines is thus constantly doing the work for which it is most suitable, and it is thus possible to obtain at any power a consumption of steamwhich is considerably less than if it be effected solely by reciprocating engines or solely by turbines, To run at a reduced speed, it will sufiice to cut off steam earlier in the reciprocating engine, the admission-pressure remaining practically The efficiency of the whole engine plant remains high, because the expansion in the reciprocating engine increases, while it diminishes in the turbines. With this arrangement a ship can enter and leave a port very easily, as without modifying the supply of steam it is easy to run forward or backward with the central shaft by simply operating the link-motion valve-gear. It is also possible to cause the side shafts to move in one direction or the other by means of the stop-valves of the turbines. For instance, the turbine 4 will be caused to run backward by closing the valve 7 and opening the valve 9, and, conversely, the forward running is resumed by closing the valve 9 and opening the valve 7. This possibility of running backward separately each of the three shafts enables a great flexibility to be imparted to a ship in maneuvering. The power exerted by the reciprocating engine at maximum speed is generally about one-third of the total power or a little higher.

In case of any one of the three engines breaking down an arrangement is provided permitting to isolate it and to run with the other engines. This arrangementis as follows: Each of the steam-pipes 3 and 5 leading to the turbines is provided with a valve (17 or 18) which permits of the steam being cut ofi from either one of the turbines. If, on the contrary, it is wished to supply the turbines with steam direct from the boilers in case of a breakdown of the reciprocating engine, this direct supply of steam may be effected through the steampipes 19 and 20, fitted with stop valves. Lastly, the pipes 21 and 22 are connected to the condensers 1 1 and 12, respectively, by pipes or passages 23 and 2a, which are provided with automatic exhaust-valves. These valves prevent the pressure from rising too high in the intermediate pipes 3 and 5 should the stopvalve of either one of the turbines happen to be closed.

In large ships it is advisable to provide more than one turbine on each side of the reciprocating engine, as shown in figure. Each group of side turbines is connected on the one hand to the reciprocating engine and on the other hand to the boiler or to the condenser exactly as in the arrangement of the single side turbines shown in Figs. 1 and 2.

The two turbines at each side of the reciprocating engine are reversible and arranged in series. 6., they are traversed successively by steam-there being thus an intermediatepressure turbine and a low-pressure turbine on each side of the reciprocating engine.

By opening the valve 25 steam is supplied to the forward-running turbines, the steam passing then through the pipe 26 in the second turbine, which is not provided with any stop-valve, and lastly through the pipe 28 into the condenser 27.

Although not shown in the drawings, in order to simplify the figure the forward and backward running turbines operating each shaft are presumed to be inclosed in a single casing. They can, however, be each inclosed in a separate casing.

In the arrangement just described the whole of the steam passes first through the reciproeating engine and then into the turbines, wherein it completes its expansion before exhausting into the condenser. A separate supply, however, is preferably provided in case the reciprocating engines should break down. This separate supply permits also of the supply of steam to the turbines being increased, and eonseq uently increase their power. This arrangement is most suitable for large ships; but for small boats, such as torpedo-boats and destroyers, it can be so simplified and modified as to secure a good utilization of the steam despite the great variations of speed these vessels are subjected to. It must be considered that while the full speed may be as much as from twenty-five to thirty knots the ordinary service speed is not more than fourteen or is in some cases as low as ten knots. Under these conditions the power exerted by the engines at the reduced speed must not be more than about one-fifteenth of the power at full speed. In order to insure a good utilization of the steam with so great a reduction of speed, it is necessary to give less preponderance to the reciprocating engine and then for the full-speed running to resort normally to a separate supply of steam to the turbines, which separate supply of steam is provided for in the arrangement previously described.

Figs. 4: and 5 show a modified arrangement, in which 31 represents the double or triple expansion reciprocating engine, 32 the highpressure turbine, 33 the low-pressu re turbine, and 34c the condenser.

The reciprocating engine drives a propeller shaft which is distinct from the two propellershafts driven by the high and low pressure turbines. Steam is supplied to the reciprocating engine by the pipe 35 and escapes therefrom by the pipe 36 and passes through the pipe 37 into the high-pressure turbine 32. After having done work in the high-pressure turbine the steam passes through the pipe 38 into the low-pressure turbine 33 and thence through the pipe 39 into the condenser 34. A valve 40 is provided to direct the steam exhausting from the reciprocating engine directlyinto thecondenser when desired. \Vhen, however, the ship is running under normal working conditions, this valve directs the steam toward thehigh-pressure turbine. Thus the steam which exhausts from the reciprocating engine passes into the high-pressure turbine and into the low-pressure turbine. The

' opening 41, through which this steam passes into the high-pressure turbine, is entirely separate from the steam-admission pipe 42. If, for instance, the high-pressure turbine consists of fifteen revolving wheels traversed in succession by steam, the opening 11 will be arranged between the eleventh and twelfth revolving wheels, so that the steam which enters the turbine by this opening will act upon the four last wheels. Under these con- IIC ditions the exhaust back pressure of the reciprocating engine cannot exceed a certain limit of, say, one and one-half to two atmospheres of absolute pressure.

hen running at a reduced speedsay from ten to thirteen knotssteam is supplied only to the reciprocatingengine, the steam passing therefrom into the high-pressure turbine and then into the low-pressure turbine drives all the screw-propeller shafts. If the steam be exhausted directly from the reciprocating eugine into the condenser, the high-pressure and low-pressure turbines would not be driven and their screw-propellers would oppose the motion of the ship instead of assisting it. If steam were supplied to the intermediate pipe 38, between the high and low pressure turbines, the low-pressure turbine would work, but the high-pressure one would not. The arrangement shown causes the steam to pass successively through all the engines and permits, consequently, to secure the highest possible economy.

When it is wished to accelerate the speed of a ship, it suflices to supply steam to the high-pressure turbine through the supplypipe 42. This additional steam-supply traverses the whole of the high-pressure turbine before reaching the low-pressure turbine. In consequence of the supply of steam the pressure rises progressively at the opening 41, through which the steam exhausts from the reciprocating engine; but this pressure never rises sufficiently to affect in a marked manner the action of the reciprocating engine. On the contrary, the ratio of expansion of the latter decreases and its mechanical output increases.

Having thus described and ascertained the nature of my invention and in what manner the same may be performed, I declare that what I claim is* 1. Means for propelling ships, consisting of a reciprocating engine driven by high-pressure steam direct from the boiler, a screwpropeller shaft operated thereby, turbines arranged on both sides of the said engine and operated by the steam exhausting from the engine, propeller-shafts operated by the turbines, means for conducting the steam from the engine into the turbines, means for operating the engine independently of the turbine, and means for driving the turbines by steam direct from the boiler and independently of the engine.

2. Means for propelling ships, consisting of a reciprocating engine driven by high-pressure steam direct from the boiler, a screwpropeller shaft operated by the engine, turbines arranged on both sides of the engine, operated by the steam exhausting from the engine and rotated in either direction, propeller-shafts driven by said turbines, means for directing the steam from the engine into the turbines either for forward or backward propeller shaft operated by said engine, turbines arranged on both sides of the engine, operated by the steam exhausting from the engine and rotatable in either direction, propeller-shafts driven by the turbines, means for directing the steam from the engine to the turbines, valves arranged in said means and adapted when operated to regulate the supply of steam to the turbines, thereby insuring backward or forward running of the turbines, and means for driving the turbines by steam direct from the boiler and independent of the engine.

4. Means for propelling ships, comprising a reciprocating'engine driven by high-pressure steam direct from the boiler, a screwpropeller shaft operated by the engine, turbines arranged on both sides of the engine,

operated by the steam exhausting from the engine and rotatable in either direction, screwpropeller shafts driven by the turbines, means for conducting the steam from the engine to the turbines, valves arranged in said means for regulating the supply of steam to the turbines, thereby governing the direction of movement thereof, a condenser, conduits for connecting the condenser with the said means, automatic exhausting-valves for the said conduits, and means for driving the turbines by steam direct from the boiler and independent of the engine. 7

5. Means for propelling ships, comprising a reciprocating engine driven by high-pressure steam direct from the boiler, a screwpropeller shaft operated by the engine, turbines arranged on both sides of the engine, operated by the steam exhausting from the engine and rotatable in either direction, screwpropeller shaft driven by the turbines, means for conducting the steam from the engine to the turbines, valves arranged in said means for regulating the supply of steam to the turbines, thereby governing the direction of movement thereof, a condenser, conduits for connecting the condenser with the said means,.

automatic exhausting-valves for said conduits, and steam-supply pipes connecting the turbines directly with the boiler and provided with stop-valves.

6. Means for propelling ships, comprising the combination with a reciprocating engine, of a set of turbines on either side thereo f, one of each set being an intermediate-pressure turbine and the. other a low-pressure turbine, conduits for connecting the engine with the intermediate pressure turbines, stop valves in said conduits for regulating the direction of movement of the said intermediate-pressure turbines, conduits for connecting the intermediate-pressure turbines with the low-pressure turbines, a condenser, and. conduits for connecting the low-pressure turbine with the condenser.

7. Means for propelling ships, comprising the combination with a reciprocating engine, of a set of turbines on either side thereof, one turbine of each set being an intermediatepressure turbine and the other a low-pressure turbine, conduits communicating with the engine and with the intermediate-pressure turbines for conducting steam to said turbines at some intermediate point in the series of wheels thereof, stop-valves in said conduits for regulating the direction of movement of the in-.

termediate-pressure turbines, means for driving the intermediate-pressure turbines direct from the boiler and independently of the engine, conduits for connecting the intermediate-pressure turbines with the low-pressure turbines, a condenser, and conduits for connecting the low-pressure turbines with the condenser.

8. Means for propelling ships, comprising a reciprocating engine driven directly from the boiler, a screw-propeller shaft operated thereby, turbines operated by the steam exhausting from the said engine, propeller-shafts driven by said turbines, means for conducting steam from the reciprocating engine to the turbines, means for operating the engine independent of the turbines, and means for driving the turbines by steam direct from the boiler and independent of the engine.

9. Means for propelling ships, comprising a reciprocatory steam-engine driven direct from the boiler, a screw-propeller shaft oper- 10. Means for propelling ships, comprising a reciprocating engine operated by a motive fluid, a propeller-shaft driven by said engine, turbines operated by the exhaust of motive fluid from said engine, propeller-shafts driven by said turbines, means for conducting the motive fluid from the engine to the turbines, means for operating the engine independent of the turbines, and means for operating the turbines independent of the engine.

11. Means for propelling ships, comprising a reciprocating engine operated by a motive fluid, a propeller-shaft driven by said engine, turbines operated by the exhaust of motive fluid from said engine and operable in either direction, propeller-shafts driven by said turbines, means for conducting the motive fluid from the engine to the turbine, means for operating the engine independent of the turbines, and means for operating the turbines independent of the engine.

In testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

AUGUSTE RATEAU. Witnesses:

HIPPOLYTE YOTTE, PAUL BLUM. 

